Diagnosis and surgical management of free-floating thrombus within the carotid artery

Free-floating thrombus (FFT) of the carotid artery is a rare condition of currently unknown etiology. Less than 150 cases have been described in the published world literature to date.

We present 6 consecutive cases of carotid FFT, identified prospectively from 5000 carotid duplex scans over a 34-month period in a single tertiary center for vascular surgery.

All 6 cases involved the left carotid bifurcation in neurologically symptomatic individuals. In 5 of the 6 cases, FFT occurred in the absence of a significantly stenosing atheromatous plaque and was not associated with an elevation in velocity on duplex. The patients were all treated with surgical thromboendarterectomy, with good result.

Duplex imaging can underestimate the degree of stenosis. Free-floating thrombus presents a challenge in diagnosis due to its rapidly evolving nature. The management of FFT by acute thromboendarterectomy appears to be safe and effective in limiting further focal neurological sequelae.